Just before he made his early exit from the G-7 summit in Charlevoix, Quebec, Mr Trump told reporters: "I feel that Kim Jong Un wants to do something great for his people and he has that opportunity".
By sitting down with an American president - a longtime goal of North Korea's government - Kim's regime is advancing its effort to establish its "reputation, respect, and credibility as a nuclear weapon state", said Michael J. Green, senior vice president for Asia and Japan Chair at the Center for Strategic and International Studies.
Kim reaffirmed that he would "work toward complete denuclearization of the Korean peninsula", though there was no indication the two men had agreed on what that would mean.
But when pressed by reporters, the secretary of state would not say whether that could include reduction of the number of or removal of USA troops in South Korea. Korean Central News Agency (KCNA) mentioned that the summit is being held "under the great attention and expectation of the whole world".
North Korea said Kim Jong Un and President Donald Trump will discuss "denuclearization" and "durable peace" on the Korean peninsula during their upcoming summit.
The US side however reportedly believes that an immediate tangible outcome is unlikely following the meet.
The report said North Korea "operates an all-encompassing indoctrination machine that takes root from childhood to propagate an official personality cult and to manufacture absolute obedience" to Mr Kim.
The pair made brief remarks as they sat together before the world's media as the historic summit got under way, with the USA leader insisting "we will have a terrific relationship I have no doubt". "All that I think gave them confidence that this was the right site, the right choice".
Merkel: G7 agree on commitment to rules-based trade
Trump said he pushed for the elimination of trade barriers, including subsidies and tariffs, at the G-7 meeting. Throughout the summit, photographers captured photos of the tension between Trump and other world leaders.
Rodman arrived in Singapore around midnight Monday, hours before President Donald Trump was set to meet Kim for an historic summit.
Trump said over the weekend that he would know if Kim is serious about brokering peace within "a minute" of meeting him.
"We had a historic meeting and chose to leave the past behind and we are about to sign the historic document", Kim said through a translator.
Tuesday marked the first meeting between a sitting US president and a North Korean leader.
Trump was flanked in the larger meeting by chief of staff John Kelly, Secretary of State Mike Pompeo and national security adviser John Bolton.
Inside, they sat alongside each other against a backdrop of North Korean and US flags, with Kim beaming broadly as the USA president gave him a thumbs up.
Kim's summit with Trump has captured intense global attention after a turn to diplomacy in recent months after serious fears of war previous year amid North Korean nuclear and missile tests.
Pompeo laid out some of the USA cards on Monday, saying the administration was sticking to its demand for the complete, verifiable and irreversible denuclearization of the North.